Electronic Letters to Improve Patient Activation in IHD: The NUDGE-IHD Trial (NUDGE-IHD)

September 2, 2026 updated by: Tor Biering-Sørensen

NUDGE-IHD: A Nationwide Pragmatic Randomized Trial of Electronic Nudges to Increase Patient Activation and Reduce Cardiovascular Events in Ischemic Heart Disease

The goal of this clinical trial is to learn whether simple electronic information letters can increase patient activation and improve risk-factor monitoring in adults in Denmark with ischemic heart disease (IHD) who have LDL cholesterol above the recommended treatment target. A subgroup of participants with elevated lipoprotein(a) [Lp(a)] will also be randomized to receive an additional information letter.

The main questions the study aims to answer are:

  • Does sending an electronic letter about elevated LDL cholesterol increase the proportion of patients who have at least one LDL-cholesterol test within 6 months?
  • Does sending an electronic letter about elevated LDL cholesterol reduce major adverse cardiovascular events (cardiovascular death, myocardial infarction, or stroke) over 5 years?
  • Among patients with ischemic heart disease and elevated Lp(a), does receiving an information letter about Lp(a) increase the proportion who have at least one LDL-cholesterol test within 6 months, and does it reduce major adverse cardiovascular events over 5 years?

Because this is a randomized trial, researchers will compare people who receive the electronic letter(s) with people who do not receive any letter to determine whether the letters encourage patients to take action, such as obtaining laboratory tests or contacting their doctor.

Participants will:

  • Receive an electronic letter through Denmark's national digital mailbox system (Digital Post) or receive no letter, depending on random assignment.
  • Continue their usual health care, with no additional visits, treatments, or procedures required for the study.
  • Have all study information collected from existing Danish nationwide health registries.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study is a nationwide, pragmatic, registry-based, nested factorial randomized trial conducted in Denmark. The trial evaluates whether simple electronic information letters ("nudges") can increase patient activation and support guideline-directed risk-factor monitoring among persons with ischemic heart disease (IHD) who have LDL cholesterol levels above guideline-recommended treatment targets in routine clinical care.

The primary study population consists of adults with documented ischemic heart disease and LDL cholesterol above the recommended target level. Eligible participants are identified using Danish nationwide health registries and randomized 1:1 to receive either an electronic information letter addressing elevated LDL cholesterol (the "LDL letter") or no letter. The LDL letter provides general, non-technical information about LDL cholesterol as a cardiovascular risk factor in ischemic heart disease and encourages recipients to consult their physician if relevant.

A secondary study population is defined as a subset of the primary population with elevated lipoprotein(a) [Lp(a)] levels identified from laboratory registry data. Participants in this subgroup are independently randomized 1:1 to receive or not receive an additional electronic information letter addressing elevated Lp(a) (the "Lp(a) letter"). The Lp(a) letter provides information on Lp(a) as a genetically determined and independent cardiovascular risk factor and emphasizes the importance of optimizing other modifiable risk factors. The two randomizations are conducted independently, with the LDL letter randomization stratified by elevated Lp(a) status, resulting in a nested factorial design in which participants with elevated Lp(a) may receive no letter, the LDL letter only, the Lp(a) letter only, or both letters.

All intervention letters are delivered through Denmark's mandatory national digital mailbox system (Digital Post). The interventions are informational and non-invasive. The study does not involve any in-person visits, clinical procedures, or changes to usual medical care.

The trial has dual primary endpoints, evaluated within each of the two independently randomized comparisons: (1) disease-related patient activation, defined as the proportion of participants with at least one LDL cholesterol measurement recorded within 6 months after randomization; and (2) major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, myocardial infarction, or stroke, within 5 years after randomization. The trial meets its objective if either primary endpoint reaches statistical significance at its prespecified alpha level; each addresses a distinct question and is interpreted on its own merits.

Secondary outcomes are general patient activation, assessed by the number of healthcare contacts in general practice or outpatient hospital settings, and cardiometabolic risk-factor monitoring, defined as the proportion of participants with at least one cardiometabolic blood test (lipid profile, hemoglobin A1c, or creatinine) within 6 months after randomization. Additional exploratory outcomes related to laboratory testing, healthcare utilization, medication use, and clinical events are assessed during longer-term follow-up.

All baseline characteristics, outcomes, and follow-up data are obtained from Danish nationwide health and administrative registries. Due to the registry-based and informational nature of the interventions, informed consent is not required. Data for the first primary endpoint and for the secondary endpoints are retrieved 6 months after randomization; data for the second primary endpoint are retrieved 5 years after randomization.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
123000

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Denmark
    • Region Sjælland
      • Hellerup, Region Sjælland, Denmark, 2900
        • Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Hellerup, 2900
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion criteria (primary study population)

  • Alive and resident in Denmark on the identification date
  • Diagnosis of IHD defined as an A (action) diagnosis code of I20-I25 in the Danish National Patient Register, first registered > 6 months prior to the identification date but after January 1, 2000
  • Latest available LDL-C is over 1.4 mmol/l measured up to 3 years prior to the identification date, defined using NPU codes NPU01568, NPU10171 or DNK35308 from the Danish National Laboratory Register
  • Age >= 18 years and <= 85 years on the identification date

Exclusion criteria

  • Nursing home residents
  • Exemption from, and thus no access to, Digital Post

Definition of the elevated Lp(a) subgroup (secondary study population) Participants in the primary study population who, in addition, have an elevated Lp(a) level recorded at any time prior to the identification date, identified in the Danish National Laboratory Register using NPU codes NPU21687 or NPU19840. Elevated Lp(a) is defined as >= 105 nmol/L or >= 50 mg/dL. Only participants in this subgroup undergo the second randomization to the Lp(a) letter.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Health Services Research
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: LDL letter only
Participants randomized to the LDL-C letter and not to the Lp(a) letter.
Behavioral: LDL-C information letter
An electronically delivered informational letter communicating the participant's elevated LDL-C level and its relevance to IHD, with encouragement to consult their physician if relevant. Delivered via the Danish Digital Post system.
Experimental: Lp(a) letter only
Participants randomized to the Lp(a) letter but not to the LDL-C letter.
Behavioral: Lp(a) information letter
An electronically delivered informational letter describing elevated Lp(a) as a genetically determined cardiovascular risk factor, with encouragement to discuss risk factor optimization with a physician if relevant.
No Intervention: No letter
Participants randomized to neither the LDL-C letter nor the Lp(a) letter.
Experimental: LDL-C and Lp(a) letter
Participants randomized to both the LDL-C letter and the Lp(a) letter.
Behavioral: Lp(a) information letter
An electronically delivered informational letter describing elevated Lp(a) as a genetically determined cardiovascular risk factor, with encouragement to discuss risk factor optimization with a physician if relevant.
Behavioral: LDL-C information letter
An electronically delivered informational letter communicating the participant's elevated LDL-C level and its relevance to IHD, with encouragement to consult their physician if relevant. Delivered via the Danish Digital Post system.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
the proportion of participants with at least one LDL-C measurement within 6 months following randomization
Time Frame: 6 months after randomization
Whether the participant has at least one LDL-C laboratory measurement recorded in the Danish national laboratory registries within 6 months after randomization
6 months after randomization
Proportion of participants experiencing a major adverse cardiovascular event (MACE) within 5 years following randomization
Time Frame: 5 years after randomization
Proportion of participants experiencing a major adverse cardiovascular event, defined as the composite of cardiovascular death, myocardial infarction, or stroke, ascertained from Danish nationwide health and administrative registries within 5 years after randomization.
5 years after randomization

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of healthcare contacts (general practice or outpatient hospital) within 6 months following randomization
Time Frame: 6 months after randomization
Total number of healthcare contacts, defined as general practice contacts (in-person, telephone, or electronic) or outpatient hospital visits, recorded in national registries within 6 months after randomization.
6 months after randomization
At least one cardiometabolic blood test
Time Frame: Within 6 months after randomization
Proportion of participants with at least one cardiometabolic blood test (lipid profile, hemoglobin A1c, or creatinine) recorded in Danish nationwide laboratory registries within 6 months after randomization.
Within 6 months after randomization

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Tor Biering-Sørensen

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Novartis

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2031

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 9, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 28, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 2, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • NUDGE-IHD

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Data will be collected from Danish administrative health registries, which are subject to Danish legislation and can only be made available to a third party under certain conditions. Please contact the sponsor-investigator in case of any inquiries.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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